Buggy code:
public class EditPeopleControlSet extends PopupControlSet { public static final String EXTRA_TASK_ID = "task" ; private Task task ; private final ArrayList < Metadata > nonSharedTags = new ArrayList < Metadata > ( ) ; @ Autowired ActFmPreferenceService actFmPreferenceService ; @ Autowired ActFmSyncService actFmSyncService ; @ Autowired TaskService taskService ; @ Autowired MetadataService metadataService ; @ Autowired ExceptionService exceptionService ; @ Autowired TagDataService tagDataService ; private final PeopleContainer sharedWithContainer ; private final CheckBox cbFacebook ; private final CheckBox cbTwitter ; private final View sharedWithRow ; private final View sharedWithView ; private final Dialog sharedWithDialog ; private final ListView assignedList ; private final TextView assignedDisplay ; private final EditText assignedCustom ; private final View assignedClear ; private final ArrayList < EditPeopleControlSet . AssignedToUser > listValues = new ArrayList < EditPeopleControlSet . AssignedToUser > ( ) ; private String saveToast = null ; private final int loginRequestCode ; public EditPeopleControlSet ( Activity activity , int viewLayout , int displayViewLayout , int title , int loginRequestCode ) { } @ Override public void readFromTask ( Task sourceTask ) { } public View getSharedWithRow ( ) { } private View getSharedWithView ( ) { } @ SuppressWarnings ( "nls" ) private void setUpData ( ) { } @ SuppressWarnings ( "nls" ) private void buildCollaborators ( final ArrayList < JSONObject > sharedPeople ) throws JSONException { } public static class AssignedToUser { public String label ; public JSONObject user ; public AssignedToUser ( String label , JSONObject user ) { } @ Override public String toString ( ) { } } @ SuppressWarnings ( "nls" ) private void buildAssignedToSpinner ( ArrayList < JSONObject > sharedPeople ) throws JSONException { } private class AssignedUserAdapter extends ArrayAdapter < EditPeopleControlSet . AssignedToUser > { public AssignedUserAdapter ( Context context , ArrayList < EditPeopleControlSet . AssignedToUser > people ) { } @ Override public View getView ( int position , View convertView , ViewGroup parent ) { } } private void assignToMe ( ) { } private void setUpListeners ( ) { } @ Override public String writeToModel ( Task model ) { } @ SuppressWarnings ( "nls" ) public boolean saveSharingSettings ( String toast ) { } private void makePrivateTask ( ) { } private void showSaveToast ( ) { } private class ParseSharedException extends Exception { private static final long serialVersionUID = - 4135848250086302970L ; public TextView view ; public String message ; public ParseSharedException ( TextView view , String message ) { } } @ SuppressWarnings ( "nls" ) private JSONObject parseSharedWithAndTags ( ) throws EditPeopleControlSet . ParseSharedException , JSONException { } @ SuppressWarnings ( "nls" ) private void shareTask ( final JSONObject sharedWith ) { } @ SuppressWarnings ( "nls" ) private void readTagData ( JSONArray tags ) throws JSONException { } @ SuppressWarnings ( "nls" ) protected Object [ ] buildSharingArgs ( JSONArray emails ) throws JSONException { } public void onActivityResult ( int requestCode , int resultCode , Intent data ) { if ( ( requestCode == ( loginRequestCode ) ) && ( resultCode == ( Activity . RESULT_OK ) ) ) { task . setValue ( USER_ID , ( - 2L ) ) ; <START_BUG> task . setValue ( USER , "" ) ; <END_BUG> saveSharingSettings ( saveToast ) ; } else if ( requestCode == ( loginRequestCode ) ) makePrivateTask ( ) ; } @ Override protected void refreshDisplayView ( ) { } }

Fix:
task . setValue ( USER , "{}" ) ;